Bupropion is a drug with psychotropic properties. Currently, it is used primarily as an atypical antidepressant drug. The substance is not addictive, and at the same time has a high potential to reduce withdrawal cravings in addicts.
Bupropionis an organic chemical compound from the group of cathinones. Preparations containing bupropion are researched and introduced to the pharmaceutical market as drugs used in the treatment of addiction. This is due to the ability of this substance to reduce withdrawal cravings. Also for this reason, bupropion has potential use as a food-reducing drug in the treatment of obesity.
Mechanism of action of bupropion
Bupropion is used as a drug with antidepressant properties. The primary mechanism of action of this drug is to block the reuptake of dopamine and norepinephrine in the brain.
Many antidepressants work by reducing the reuptake of the neurotransmitters serotonin and noradrenaline.
Bupropion is an unusual drug because it affects dopamine (DA) reuptake. Dopamine is an important neurotransmitter whose low concentration is involved in brain changes during depression. Most antidepressants do not affect the levels of this neurotransmitter.
Buprion - history of the drug
Bupropinone was discovered in 1969 by Nariman Mehta. Ultimately, the drug was approved by the US FDA as an antidepressant in 1985. Bupropion was first introduced to the market as Wellbutrin.
The first drug containing bupropion was quickly withdrawn from the market. This happened in 1986, less than a year after being introduced to therapy. It turned out that in clinical practice, the substance used in the recommended dose caused seizures in many patients. Ultimately, further studies established that the seizure effect was dose-dependent. In the case of Wellbutrin it was from 400 to 600 mg.
In 1989, bupropion returned to medical practice. In order to minimize the risk of side effects, the maximum daily dose has been reduced. The maximum amount of substance per day was 450 mg. The preparation was recommended to be taken in three dosesdivided daily.
Another form of the drug that guarantees greater safety is the slow-release form. It was introduced by GlaxoSmithKline under the name Wellbutrin SR. The US FDA approved this form of the drug in 1996. The preparation was recommended to be taken twice a day.
In 1997, bupropion was approved by the FDA for the treatment of nicotine addiction. The Zyban preparation has been introduced to the market, intended for smokers who want to quit.
In 2003, the FDA approved another sustained-release form of bupropion under the name Wellbutrin XL. It was enough to take the drug once a day. Due to the changed release mechanism, reduced dose and less frequent administration of the preparation, the frequency of seizures after using this drug is similar or even lower than that of other antidepressants. However, special caution is still recommended when using bupropion in people at risk of seizures.
Bupropion to treat depression
Dopamine is considered a "hedonistic" neurotransmitter. It is important for the ability to feel pleasure as well as the functioning of the brain's reward center. Its level determines the ability to engage in activities, motivations, as well as meet life and physiological needs. People with depression often have problems with activities that support life functions, such as sleep and eating.
Bupropion is used in the treatment of seasonal depression as a standalone preparation or in combination therapy with other antidepressants. This drug is often combined with preparations from the SSRI group. Bupropion has also been registered as a substance used in the prevention of seasonal depression.
An important feature that distinguishes bupropion from most antidepressants is its lack of adverse effects on sexual function. Most of the preparations used in the treatment of depression worsen the patients' erotic life.
Bupropion has no side effects leading to a decrease in libido and erectile dysfunction. There are also studies showing that this drug may be useful in the treatment of sexual dysfunction.
Bupropion in the treatment of nicotine addiction
Bupropion is also a nicotinic receptor antagonist. Thanks to this, the drug reduces nicotine craving and unpleasant withdrawal effects. For this reason, it is especially used in the treatment of nicotine addiction.
Additionally, bupropion inhibits dopamine reuptake, thereby affecting the reward system it hasimportant for the state of nicotine addiction.
From the chemical point of view, this drug resembles cathinone and phenylethylamine, i.e. substances with strong psychostimulating properties.
In addition, the stimulant effects produced by bupropion in the central nervous system are similar to those of nicotine. Thanks to this, low doses of this drug can act as a nicotine substitute during withdrawal therapy.
In 1997, studies were conducted to assess the effects of bupropion on nicotine addiction. 615 patients participated in the study. They were randomized to receive either placebo or bupropion at a dose of 100, 150 or 300 mg per day. The research work lasted for seven weeks. People suffering from depression could not participate in the study. This was to rule out the effect of the antidepressant effect on the result.
The study confirmed the beneficial effects of bupropion therapy. In tests, the proportion of patients who successfully quit smoking was 19.0% in the placebo group, 28.8% in the 100 mg bupropion group, 38.6% in the 150 mg bupropion group and 44.2% in the 300 mg bupropion group. The results were confirmed by measurements of carbon monoxide in the exhaled air.
Bupropion in the treatment of obesity
There are clinical studies showing the potential of bupropin in the treatment of obesity. However, the substance has not yet been approved for the treatment of this disease. However, a preparation containing bupropion in combination with n altrexone is available on the pharmaceutical market.
GlaxoSmithKline has in the past promoted Wellbutrin containing bupropion for purposes other than those approved by the FDA. The manufacturer presented the drug as a remedy for obesity and sexual dysfunction. It was an illegal activity. Ultimately, GlaxoSmithKline was fined $ 3 billion.
Bupropion is used in conjunction with n altrexone for chronic weight management. These two components likely influence the areas of the brain involved in regulating food intake. This applies to the hypothalamus, which is involved in the regulation of appetite. For this reason, the combined preparation containing bupropion is used in the treatment of obesity.
Another important aspect for the use of this drug in the treatment of weight disorders is its effect on the dopaminergic system. Dopamine is of particular importance to the reward center. The lack of control over food consumption is often related to the work of this center in the brain.
Side effects caused by bupropion
For the most common induced side effectsby bupropion include:
- insomnia
- headache
- dry mouth
- digestive tract disorders
- nausea and vomiting
- hypersensitivity reactions such as hives
- loss of appetite
- arousal
- irritability
- tremors
- dizziness
- taste disturbance
- visual disturbance
- tinnitus
- increase in blood pressure
- skin redness
- sweating
- fever
- chest pain
- weakness
The most serious side effect of bupropion is seizures. The risk of a seizure depends on the drug and the dose. The prolonged release form of the preparation reduces the risk of these side effects. An increased risk of a seizure occurs in people who:
- sustained a head injury
- use other drugs that lower the convulsive excitability threshold
- are diabetic and take medication for this condition
- are addicted to alcohol
- take preparations that stimulate or reduce appetite
Inform the doctor supervising the therapy about all these situations.
When not to use bupropion?
Bupropion should not be used by people:
- who have a history of seizures
- diagnosed with a cancer of the central nervous system
- suffering from cirrhosis
- who have had a history of bulimic or anorexic episodes
- using MAO inhibitors
Sara Janowska, MA in pharmacyPhD student of interdisciplinary doctoral studies in the field of pharmaceutical and biomedical sciences at the Medical University of Lublin and the Institute of Biotechnology in Białystok. A graduate of pharmaceutical studies at the Medical University of Lublin with a specialization in Plant Medicine. She obtained a master's degree defending a thesis in the field of pharmaceutical botany on the antioxidant properties of extracts obtained from twenty species of mosses. Currently, in his research work, he deals with the synthesis of new anti-cancer substances and the study of their properties on cancer cell lines. For two years she worked as a master of pharmacy in an open pharmacy.
Read more articles by this author